An intensive campaign to combat HIV/Aids with costly antiretroviral drugs in rural South Africa has increased life expectancy by more than 11 years and significantly reduced the risk of infection for healthy individuals, according to new research. The study, published in the journal Science , comes as wealthy Western nations debate how best to stretch limited Aids funding at a time of economic stress. With an annual price tag of US$500 to US$900 per patient, antiretroviral therapy programmes have stirred debate. Critics argue that adherence to the drug regimen is low and social stigma prevents some from seeking care until they are very ill and have infected others. Cheaper remedies, such as condom distribution, male circumcision and behaviour modification, deserve more attention and funding, they say. The new economic analysis of a US$10.8 million campaign in KwaZulu-Natal province found that the drug scale-up had been highly cost-effective. The programme was administered by nurses in rural health clinics in an impoverished region of about 100,000 people. Treatment consisted primarily of daily doses of antiretroviral therapy, or ART, drugs, which patients take every day for their entire lives. Patients picked up their medication at a rural clinic once a month. In 2003, the year before the drugs were available, 29 per cent of all residents were infected with HIV and half of all deaths there were caused by Aids. Life expectancy in the region was slightly more than 49 years. By 2011, life expectancy had grown to 60-1/2 years - "the most rapid life expectancy gains observed in the history of public health", said study senior author Till Barnighausen, a global health professor at the Harvard School of Public Health.